Swiftui TabBar：点击当前选定选项卡的 TabItem 以重置视图的操作

Question

The App I am working on is based around a TabBar, and when I am on a tab I want to be able to click the tabItem again to reset the view, similar to how twitter does it in their tabBar.

I do not know how to recognize that action though. Adding a button to the TabItem is not working, addidng a tapGesture modifier isn't either, and I can't think of anything else I could try.

struct ContentView: View {
  var body: some View {
    TabView() {
      Text("Tab 1")
        .tabItem {
          Image(systemName: "star")
            .onTapGesture {
              print("Hello!")
            }
          Text("One")
        }
        .tag(0)
      
      Text("Tab 2")
        .tabItem {
          Button(action: {
            print("Hello!")
          }, label: {
            Image(systemName: "star.fill")
          })
        }
        .tag(1)
    }
  }
}

It should't automatically reset when opening the tab again, which I have seen discussed elsewhere, but when tapping the tabItem again.

What other things am I possibly missing here?

Answer 1

Here is possible solution - inject proxy binding around TabView selection state and handle repeated tab tapped before bound value set, like below.

Tested with Xcode 12.1 / iOS 14.1

struct ContentView: View {
    @State private var selection = 0
    
    var handler: Binding<Int> { Binding(
        get: { self.selection },
        set: {
            if $0 == self.selection {
                print("Reset here!!")
            }
            self.selection = $0
        }
    )}
    
    var body: some View {
        TabView(selection: handler) {
            Text("Tab 1")
                .tabItem {
                    Image(systemName: "star")
                    Text("One")
                }
                .tag(0)
            
            Text("Tab 2")
                .tabItem {
                    Image(systemName: "star.fill")
                }
                .tag(1)
        }
    }
}